SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ac4c62fb5e25cd3f74aac61de8b382fc92b2259c3781b045903ebf093708b02f' 
  AND token = 'amKXWpwj2IaEvL26JEfVQ/aLlSG8XvuTVgisZ+vx/oc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}